Pipable command to print in color?

I don't know of any utility for colored printing itself, but you can do it easily with a shell function like this:

# colorize stdin according to parameter passed (GREEN, CYAN, BLUE, YELLOW)
colorize(){
    GREEN="\033[0;32m"
    CYAN="\033[0;36m"
    GRAY="\033[0;37m"
    BLUE="\033[0;34m"
    YELLOW="\033[0;33m"
    NORMAL="\033[m"
    color=\$${1:-NORMAL}
    # activate color passed as argument
    echo -ne "`eval echo ${color}`"
    # read stdin (pipe) and print from it:
    cat
    # Note: if instead of reading from the pipe, you wanted to print
    # the additional parameters of the function, you could do:
    # shift; echo $*
    # back to normal (no color)
    echo -ne "${NORMAL}"
}
echo hi | colorize GREEN

If you want to check other colors, take a look at this list. You can add support for any color from there, simply creating an additional variable at this function with the correct name and value.

I created this function that I use in bash scripts.

# Function to echo in specified color
echoincolor () {
    case $1 in
        "red") tput setaf 1;;
        "green") tput setaf 2;;
        "orange") tput setaf 3;;
        "blue") tput setaf 4;;
        "purple") tput setaf 5;;
        "cyan") tput setaf 6;;
        "gray" | "grey") tput setaf 7;;
        "white") tput setaf 8;;
    esac
    echo "$2";
    tput sgr0
}

Then I just call it like this echoincolor green "This text is in green!"

Alternatively, use printf

# Function to print in specified color
colorprintf () {
    case $1 in
        "red") tput setaf 1;;
        "green") tput setaf 2;;
        "orange") tput setaf 3;;
        "blue") tput setaf 4;;
        "purple") tput setaf 5;;
        "cyan") tput setaf 6;;
        "gray" | "grey") tput setaf 7;;
        "white") tput setaf 8;;
    esac
    printf "$2";
    tput sgr0
}

Then just call it like this colorprintf green "This text is in green!"

Note, echo provides a trailing new line while printf does not.